This invention is directed to an elongated catheter adapted to facilitate delivery of a therapeutic or diagnostic device into a body cavity such as the left ventricle of a patient's heart, and particularly for the treatment of myocardial tissue experiencing ischemic conditions by revascularization of such tissue.
Myocardial revascularization typically involves formation of one or more channels in a patient's heart wall defining the heart chamber to treat a patient's ischemic myocardial tissue therein. The first trials of the revascularization process was made by Mirhoseini et al. See for example the discussions in Lasers in General Surgery (Williams & Wilkins; 1989), pp 216-223. Another early disclosure of this procedure is found in U.S. Pat. No. 4,658,817 (Hardy). Both of these references describe revascularization procedures which require the chest wall to be opened and which include formation of the revascularization channels through the epicardium, myocardium and endocardium, i.e. the entire heart wall.
Copending application Ser. No. 08/368,409, filed on Dec. 30, 1994, which is incorporated herein in its entirety, describes an intravascular system for percutaneous transmyocardial revascularization (PTMR) which is introduced into a peripheral artery and advanced through the patient's arterial system into the left ventricle of the patient's heart. The revascularization channels are formed through the endocardium and into the myocardium from within the left ventricle. This procedure eliminates the need of the prior intraoperative procedures which require opening the chest cavity and penetrating the entire heart wall to form a channel through the endocardium into the myocardium.
While the percutaneous method and system for introducing the revascularization device developed by Aita et al. was a substantial advance, one of the difficulties in forming revascularization channels from within a patient's left ventricle by means of a percutaneously introduced revascularization system was to accurately direct the distal tip of the channel forming device to a desired region of the patient's endocardium and to maintain the placement of the distal end of the channel forming device against a desired region of the ventricular wall at a proper angle while the heart was beating. Copending application, Ser. No 08/646,856 filed May 8, 1996, which is incorporated herein in its entirety, describes an intravascular system using one or more delivery catheters which may have a preshaped or shapeable distal extremities to facilitate directing a therapeutic or diagnostic device slidably disposed within the catheter lumen toward the region of the endocardium where the procedure is to be performed.
What has been needed is a guiding or delivery catheter with the maneuverability desired for advancing through the patient's vasculature yet having sufficient strength and rigidity to support a channel forming device within the patient's heart chamber. The present invention satisfies these and other needs.